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3.5 mm -> XLR adaptor?

I want to make an adaptor cable which has a 3.5 mm stereo plug on one end and a male XLR plug on the other end.

The XLR socket (which the cable will plug into) is a microphone input and I want to be able to connect a CD/mp3 player to it via the adaptor cable.

So, how do I wire it? And, do I need to include any components? I know most microphones are between 100 - 600 ohm and speaker outputs are much lower like 8 or 16 ohm. Will I need to add a resistor or whatever to match the mp3 player to mic. input?

TIA

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Reply to
Zyxak
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XLR pin 1 is ground, pin2 is hot, pin 3 is cold.

The XLR input is a mono signal, so you will need to use 2 inputs to connect the stereo output of the CD/MP3 player, each with an XLR connector. One XLR connector is wired to the 3.5mm plug tip, the other to the ring. The sleeve of the 3.5mm plug is ground.

Since you won't be using balanced inputs, connect the cold pin of the XLR to the ground pin.

The you will need to adjust your input trim to handle the line output from the CD player without overloading the input.

Reply to
swanny

I would think that only one XLR plug would be needed if the amp is only mono. Connect a 100 ohm (not sure about the value) resistor in series with the tip and ring of the 3.5mm stereo plug. Join the resistors together and connect to pin 2 in the XLR plug.

And as Swanny wrote, connect pin 3 to ground.

Russell Griffiths.

Reply to
rg26ce1991

On 29/12/05 23:28, snipped-for-privacy@hotmail.com uttered the following...

I'm using a 3.5 mm stereo phono plug - tip/ring/sleeve. Do I run tip and ring (L and R channels) together into one resistor or a resistor on each then connect the resistors to pin 2? When you say " not sure about the value" do you mean power rating? What would you suggest?

Does the sleeve connect directly to ground?

One last thing, on closer inspection I find that the XLR socket I want to connect to has 5 connectors not the standard 3. From various sources I found through google I see that pins 1, 2 and 3 are still used for the same connections for a microphone. Yes?

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Reply to
Zyxak

one resistor each...

It's generally bad to connect two audio outputs directly together, this is more true of loudspeaker outputs) but headphone outputs are often just small versions of loudspeaker outputs. and left and right count as separate outputs.

apropriate resistance... there's way too much power in the headphone socket to send it all directly into the microphone input so it'll mean you need to run it with the volume turned down... with casette players things like motor noise tends to be more noticeable with the volumen turned down. dunno about mp3 players cpu noise?

for power rating anything should be fine (a common size is 1/4W)

no. to cold (pin 3)

if it didn't regular microphones wouldn't work with it.

are the extra pins for sterio?

Bye. Jasen

Reply to
Jasen Betts

Thanks for answering those questions Jasen, you saw them long before I did.

Russell.

Reply to
rg26ce1991

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